[2/3,media] videobuf2-dma-streaming: new videobuf2 memory allocator
Commit Message
Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
---
drivers/media/video/Kconfig | 6 +-
drivers/media/video/Makefile | 1 +
drivers/media/video/videobuf2-dma-streaming.c | 187 ++++++++++++++++++++++++++
include/media/videobuf2-dma-streaming.h | 24 ++++
4 file modificati, 217 inserzioni(+). 1 rimozione(-)
create mode 100644 drivers/media/video/videobuf2-dma-streaming.c
create mode 100644 include/media/videobuf2-dma-streaming.h
Comments
Hello,
I'm really sorry for a late reply, but I was a bit busy with other stuff.
On Tuesday, July 31, 2012 10:17 PM Federico Vaga wrote:
> Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
> ---
> drivers/media/video/Kconfig | 6 +-
> drivers/media/video/Makefile | 1 +
> drivers/media/video/videobuf2-dma-streaming.c | 187 ++++++++++++++++++++++++++
> include/media/videobuf2-dma-streaming.h | 24 ++++
> 4 file modificati, 217 inserzioni(+). 1 rimozione(-)
> create mode 100644 drivers/media/video/videobuf2-dma-streaming.c
> create mode 100644 include/media/videobuf2-dma-streaming.h
>
> diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> index be6d718..6c60b59 100644
> --- a/drivers/media/video/Kconfig
> +++ b/drivers/media/video/Kconfig
> @@ -59,6 +59,10 @@ config VIDEOBUF2_DMA_NC
> select VIDEOBUF2_CORE
> select VIDEOBUF2_MEMOPS
> tristate
> +config VIDEOBUF2_DMA_STREAMING
> + select VIDEOBUF2_CORE
> + select VIDEOBUF2_MEMOPS
> + tristate
>
> config VIDEOBUF2_VMALLOC
> select VIDEOBUF2_CORE
> @@ -844,7 +848,7 @@ config STA2X11_VIP
> tristate "STA2X11 VIP Video For Linux"
> depends on STA2X11
> select VIDEO_ADV7180 if VIDEO_HELPER_CHIPS_AUTO
> - select VIDEOBUF_DMA_CONTIG
> + select VIDEOBUF2_DMA_STREAMING
This doesn't look like a part of this part.
> depends on PCI && VIDEO_V4L2 && VIRT_TO_BUS
> help
> Say Y for support for STA2X11 VIP (Video Input Port) capture
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index 30234af..c1a08b9e 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -140,6 +140,7 @@ obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o
> obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o
> obj-$(CONFIG_VIDEOBUF2_DMA_SG) += videobuf2-dma-sg.o
> obj-$(CONFIG_VIDEOBUF2_DMA_NC) += videobuf2-dma-nc.o
> +obj-$(CONFIG_VIDEOBUF2_DMA_STREAMING) += videobuf2-dma-streaming.o
>
> obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
>
> diff --git a/drivers/media/video/videobuf2-dma-streaming.c b/drivers/media/video/videobuf2-
> dma-streaming.c
> new file mode 100644
> index 0000000..d96d3d9
> --- /dev/null
> +++ b/drivers/media/video/videobuf2-dma-streaming.c
> @@ -0,0 +1,187 @@
> +/*
> + * videobuf2-dma-streaming.c - DMA streaming memory allocator for videobuf2
> + *
> + * Copyright (C) 2012 Federico Vaga <federico.vaga@gmail.com>
> + * *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/pagemap.h>
> +#include <linux/dma-mapping.h>
> +
> +#include <media/videobuf2-core.h>
> +#include <media/videobuf2-dma-streaming.h>
> +#include <media/videobuf2-memops.h>
> +
> +struct vb2_streaming_conf {
> + struct device *dev;
> +};
> +struct vb2_streaming_buf {
> + struct vb2_streaming_conf *conf;
> + void *vaddr;
> +
> + dma_addr_t dma_handle;
> +
> + unsigned long size;
> + struct vm_area_struct *vma;
> +
> + atomic_t refcount;
> + struct vb2_vmarea_handler handler;
> +};
> +
> +static void vb2_dma_streaming_put(void *buf_priv)
> +{
> + struct vb2_streaming_buf *buf = buf_priv;
> +
> + if (atomic_dec_and_test(&buf->refcount)) {
> + dma_unmap_single(buf->conf->dev, buf->dma_handle, buf->size,
> + DMA_FROM_DEVICE);
> + free_pages_exact(buf->vaddr, buf->size);
> + kfree(buf);
> + }
> +
> +}
> +
> +static void *vb2_dma_streaming_alloc(void *alloc_ctx, unsigned long size)
> +{
> + struct vb2_streaming_conf *conf = alloc_ctx;
> + struct vb2_streaming_buf *buf;
> + int err;
> +
> + buf = kzalloc(sizeof *buf, GFP_KERNEL);
> + if (!buf)
> + return ERR_PTR(-ENOMEM);
> + buf->vaddr = alloc_pages_exact(size, GFP_KERNEL | GFP_DMA);
> + if (!buf->vaddr) {
> + err = -ENOMEM;
> + goto out;
> + }
> + buf->dma_handle = dma_map_single(conf->dev, buf->vaddr, size,
> + DMA_FROM_DEVICE);
> + err = dma_mapping_error(conf->dev, buf->dma_handle);
> + if (err) {
> + dev_err(conf->dev, "dma_map_single failed\n");
> +
> + free_pages_exact(buf->vaddr, size);
> + buf->vaddr = NULL;
> + goto out_pages;
> + }
> + buf->conf = conf;
> + buf->size = size;
> + buf->handler.refcount = &buf->refcount;
> + buf->handler.put = vb2_dma_streaming_put;
> + buf->handler.arg = buf;
> +
> + atomic_inc(&buf->refcount);
> + return buf;
> +
> +out_pages:
> + free_pages_exact(buf->vaddr, buf->size);
> +out:
> + kfree(buf);
> + return ERR_PTR(err);
> +}
> +
> +static void *vb2_dma_streaming_cookie(void *buf_priv)
> +{
> + struct vb2_streaming_buf *buf = buf_priv;
> +
> + return (void *)buf->dma_handle;
> +}
> +
> +static void *vb2_dma_streaming_vaddr(void *buf_priv)
> +{
> + struct vb2_streaming_buf *buf = buf_priv;
> +
> + if (!buf)
> + return NULL;
> + return buf->vaddr;
> +}
> +
> +static unsigned int vb2_dma_streaming_num_users(void *buf_priv)
> +{
> + struct vb2_streaming_buf *buf = buf_priv;
> +
> + return atomic_read(&buf->refcount);
> +}
> +
> +static int vb2_dma_streaming_mmap(void *buf_priv, struct vm_area_struct *vma)
> +{
> + struct vb2_streaming_buf *buf = buf_priv;
> + unsigned long pos, start = vma->vm_start;
> + unsigned long size;
> + struct page *page;
> + int err;
> +
> + /* Try to remap memory */
> + size = vma->vm_end - vma->vm_start;
> + size = (size < buf->size) ? size : buf->size;
> + pos = (unsigned long)buf->vaddr;
> +
> + while (size > 0) {
> + page = virt_to_page((void *)pos);
> + if (!page) {
> + dev_err(buf->conf->dev, "mmap: virt_to_page failed\n");
> + return -ENOMEM;
> + }
> + err = vm_insert_page(vma, start, page);
> + if (err) {
> + dev_err(buf->conf->dev, "mmap: insert failed %d\n", err);
> + return -ENOMEM;
> + }
> + start += PAGE_SIZE;
> + pos += PAGE_SIZE;
> +
> + if (size > PAGE_SIZE)
> + size -= PAGE_SIZE;
> + else
> + size = 0;
> + }
> +
> +
> + vma->vm_ops = &vb2_common_vm_ops;
> + vma->vm_flags |= VM_DONTEXPAND;
> + vma->vm_private_data = &buf->handler;
> +
> + vma->vm_ops->open(vma);
> +
> + return 0;
> +}
> +
> +const struct vb2_mem_ops vb2_dma_streaming_memops = {
> + .alloc = vb2_dma_streaming_alloc,
> + .put = vb2_dma_streaming_put,
> + .cookie = vb2_dma_streaming_cookie,
> + .vaddr = vb2_dma_streaming_vaddr,
> + .mmap = vb2_dma_streaming_mmap,
> + .num_users = vb2_dma_streaming_num_users,
> +};
> +EXPORT_SYMBOL_GPL(vb2_dma_streaming_memops);
> +
> +void *vb2_dma_streaming_init_ctx(struct device *dev)
> +{
> + struct vb2_streaming_conf *conf;
> +
> + conf = kmalloc(sizeof *conf, GFP_KERNEL);
> + if (!conf)
> + return ERR_PTR(-ENOMEM);
> +
> + conf->dev = dev;
> +
> + return conf;
> +}
> +EXPORT_SYMBOL_GPL(vb2_dma_streaming_init_ctx);
> +
> +void vb2_dma_streaming_cleanup_ctx(void *alloc_ctx)
> +{
> + kfree(alloc_ctx);
> +}
> +EXPORT_SYMBOL_GPL(vb2_dma_streaming_cleanup_ctx);
> +
> +MODULE_DESCRIPTION("DMA-streaming memory allocator for videobuf2");
> +MODULE_AUTHOR("Federico Vaga <federico.vaga@gmail.com>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/media/videobuf2-dma-streaming.h b/include/media/videobuf2-dma-streaming.h
> new file mode 100644
> index 0000000..89cbd06
> --- /dev/null
> +++ b/include/media/videobuf2-dma-streaming.h
> @@ -0,0 +1,24 @@
> +/*
> + * videobuf2-dma-streaming.h - DMA steaming memory allocator for videobuf2
> + *
> + * Copyright (C) 2012 Federico Vaga
> + *
> + * Author: Federico Vaga <federico.vaga@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation.
> + */
> +
> +#ifndef _MEDIA_VIDEOBUF2_DMA_STREAMING_H
> +#define _MEDIA_VIDEOBUF2_DMA_STREAMING_H
> +
> +#include <media/videobuf2-core.h>
> +#include <linux/dma-mapping.h>
> +
> +void *vb2_dma_streaming_init_ctx(struct device *dev);
> +void vb2_dma_streaming_cleanup_ctx(void *alloc_ctx);
> +
> +extern const struct vb2_mem_ops vb2_dma_streaming_memops;
> +
> +#endif
> --
> 1.7.11.2
I'm aware of the fact that some system might require such method of memory allocation.
I don't want to delay merging it. I hope that one day it will be finally possible to
use dma_alloc_attrs() from dma-mapping subsystem for this purpose and extended
videobuf2-dma-contig will handle it.
Getting back to your patch - in your approach cpu cache handling is missing. I suspect
that it worked fine only because it has been tested on some simple platform without
any cpu caches (or with very small ones). Please check the following thread:
http://www.spinics.net/lists/linux-media/msg51768.html where Tomasz has posted his
ongoing effort on updating and extending videobuf2 and dma-contig allocator.
Especially the patch http://www.spinics.net/lists/linux-media/msg51776.html will be
interesting for you, because cpu cache synchronization (dma_sync_single_for_device /
dma_sync_single_for_cpu) should be called from prepare/finish callbacks.
Best regards
> Getting back to your patch - in your approach cpu cache handling is
> missing. I suspect that it worked fine only because it has been
> tested on some simple platform without any cpu caches (or with very
> small ones).
Is missing from the memory allocator because I do it on the device
driver. The current operations don't allow me to do that in the memory
allocator.
> Please check the following thread:
> http://www.spinics.net/lists/linux-media/msg51768.html where Tomasz
> has posted his ongoing effort on updating and extending videobuf2 and
> dma-contig allocator. Especially the patch
> http://www.spinics.net/lists/linux-media/msg51776.html will be
> interesting for you, because cpu cache synchronization
> (dma_sync_single_for_device / dma_sync_single_for_cpu) should be
> called from prepare/finish callbacks.
You are right, it is interesting because avoid me to use cache sync in
my driver. Can I work on these patches?
From this page I understand that these patches are not approved yet
https://patchwork.kernel.org/project/linux-media/list/?page=2
Hello,
On Friday, August 24, 2012 3:23 PM Federico Vaga wrote:
> > Getting back to your patch - in your approach cpu cache handling is
> > missing. I suspect that it worked fine only because it has been
> > tested on some simple platform without any cpu caches (or with very
> > small ones).
>
> Is missing from the memory allocator because I do it on the device
> driver. The current operations don't allow me to do that in the memory
> allocator.
Memory allocator module is much more appropriate place for it. dma-sg
allocator also needs a huge cleanup in this area...
> > Please check the following thread:
> > http://www.spinics.net/lists/linux-media/msg51768.html where Tomasz
> > has posted his ongoing effort on updating and extending videobuf2 and
> > dma-contig allocator. Especially the patch
> > http://www.spinics.net/lists/linux-media/msg51776.html will be
> > interesting for you, because cpu cache synchronization
> > (dma_sync_single_for_device / dma_sync_single_for_cpu) should be
> > called from prepare/finish callbacks.
>
> You are right, it is interesting because avoid me to use cache sync in
> my driver. Can I work on these patches?
>
> From this page I understand that these patches are not approved yet
> https://patchwork.kernel.org/project/linux-media/list/?page=2
You can take the patch which adds prepare/finish methods to memory
allocators. It should not have any dependency on the other stuff from
that thread. I'm fine with merging it either together with Your patch
or via Tomasz's patchset, whatever comes first.
Best regards
> You can take the patch which adds prepare/finish methods to memory
> allocators. It should not have any dependency on the other stuff from
> that thread. I'm fine with merging it either together with Your patch
> or via Tomasz's patchset, whatever comes first.
Thank you. I'll do the job
@@ -59,6 +59,10 @@ config VIDEOBUF2_DMA_NC
select VIDEOBUF2_CORE
select VIDEOBUF2_MEMOPS
tristate
+config VIDEOBUF2_DMA_STREAMING
+ select VIDEOBUF2_CORE
+ select VIDEOBUF2_MEMOPS
+ tristate
config VIDEOBUF2_VMALLOC
select VIDEOBUF2_CORE
@@ -844,7 +848,7 @@ config STA2X11_VIP
tristate "STA2X11 VIP Video For Linux"
depends on STA2X11
select VIDEO_ADV7180 if VIDEO_HELPER_CHIPS_AUTO
- select VIDEOBUF_DMA_CONTIG
+ select VIDEOBUF2_DMA_STREAMING
depends on PCI && VIDEO_V4L2 && VIRT_TO_BUS
help
Say Y for support for STA2X11 VIP (Video Input Port) capture
@@ -140,6 +140,7 @@ obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o
obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o
obj-$(CONFIG_VIDEOBUF2_DMA_SG) += videobuf2-dma-sg.o
obj-$(CONFIG_VIDEOBUF2_DMA_NC) += videobuf2-dma-nc.o
+obj-$(CONFIG_VIDEOBUF2_DMA_STREAMING) += videobuf2-dma-streaming.o
obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
new file mode 100644
@@ -0,0 +1,187 @@
+/*
+ * videobuf2-dma-streaming.c - DMA streaming memory allocator for videobuf2
+ *
+ * Copyright (C) 2012 Federico Vaga <federico.vaga@gmail.com>
+ * *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/dma-mapping.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-dma-streaming.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_streaming_conf {
+ struct device *dev;
+};
+struct vb2_streaming_buf {
+ struct vb2_streaming_conf *conf;
+ void *vaddr;
+
+ dma_addr_t dma_handle;
+
+ unsigned long size;
+ struct vm_area_struct *vma;
+
+ atomic_t refcount;
+ struct vb2_vmarea_handler handler;
+};
+
+static void vb2_dma_streaming_put(void *buf_priv)
+{
+ struct vb2_streaming_buf *buf = buf_priv;
+
+ if (atomic_dec_and_test(&buf->refcount)) {
+ dma_unmap_single(buf->conf->dev, buf->dma_handle, buf->size,
+ DMA_FROM_DEVICE);
+ free_pages_exact(buf->vaddr, buf->size);
+ kfree(buf);
+ }
+
+}
+
+static void *vb2_dma_streaming_alloc(void *alloc_ctx, unsigned long size)
+{
+ struct vb2_streaming_conf *conf = alloc_ctx;
+ struct vb2_streaming_buf *buf;
+ int err;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+ buf->vaddr = alloc_pages_exact(size, GFP_KERNEL | GFP_DMA);
+ if (!buf->vaddr) {
+ err = -ENOMEM;
+ goto out;
+ }
+ buf->dma_handle = dma_map_single(conf->dev, buf->vaddr, size,
+ DMA_FROM_DEVICE);
+ err = dma_mapping_error(conf->dev, buf->dma_handle);
+ if (err) {
+ dev_err(conf->dev, "dma_map_single failed\n");
+
+ free_pages_exact(buf->vaddr, size);
+ buf->vaddr = NULL;
+ goto out_pages;
+ }
+ buf->conf = conf;
+ buf->size = size;
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_dma_streaming_put;
+ buf->handler.arg = buf;
+
+ atomic_inc(&buf->refcount);
+ return buf;
+
+out_pages:
+ free_pages_exact(buf->vaddr, buf->size);
+out:
+ kfree(buf);
+ return ERR_PTR(err);
+}
+
+static void *vb2_dma_streaming_cookie(void *buf_priv)
+{
+ struct vb2_streaming_buf *buf = buf_priv;
+
+ return (void *)buf->dma_handle;
+}
+
+static void *vb2_dma_streaming_vaddr(void *buf_priv)
+{
+ struct vb2_streaming_buf *buf = buf_priv;
+
+ if (!buf)
+ return NULL;
+ return buf->vaddr;
+}
+
+static unsigned int vb2_dma_streaming_num_users(void *buf_priv)
+{
+ struct vb2_streaming_buf *buf = buf_priv;
+
+ return atomic_read(&buf->refcount);
+}
+
+static int vb2_dma_streaming_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_streaming_buf *buf = buf_priv;
+ unsigned long pos, start = vma->vm_start;
+ unsigned long size;
+ struct page *page;
+ int err;
+
+ /* Try to remap memory */
+ size = vma->vm_end - vma->vm_start;
+ size = (size < buf->size) ? size : buf->size;
+ pos = (unsigned long)buf->vaddr;
+
+ while (size > 0) {
+ page = virt_to_page((void *)pos);
+ if (!page) {
+ dev_err(buf->conf->dev, "mmap: virt_to_page failed\n");
+ return -ENOMEM;
+ }
+ err = vm_insert_page(vma, start, page);
+ if (err) {
+ dev_err(buf->conf->dev, "mmap: insert failed %d\n", err);
+ return -ENOMEM;
+ }
+ start += PAGE_SIZE;
+ pos += PAGE_SIZE;
+
+ if (size > PAGE_SIZE)
+ size -= PAGE_SIZE;
+ else
+ size = 0;
+ }
+
+
+ vma->vm_ops = &vb2_common_vm_ops;
+ vma->vm_flags |= VM_DONTEXPAND;
+ vma->vm_private_data = &buf->handler;
+
+ vma->vm_ops->open(vma);
+
+ return 0;
+}
+
+const struct vb2_mem_ops vb2_dma_streaming_memops = {
+ .alloc = vb2_dma_streaming_alloc,
+ .put = vb2_dma_streaming_put,
+ .cookie = vb2_dma_streaming_cookie,
+ .vaddr = vb2_dma_streaming_vaddr,
+ .mmap = vb2_dma_streaming_mmap,
+ .num_users = vb2_dma_streaming_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_dma_streaming_memops);
+
+void *vb2_dma_streaming_init_ctx(struct device *dev)
+{
+ struct vb2_streaming_conf *conf;
+
+ conf = kmalloc(sizeof *conf, GFP_KERNEL);
+ if (!conf)
+ return ERR_PTR(-ENOMEM);
+
+ conf->dev = dev;
+
+ return conf;
+}
+EXPORT_SYMBOL_GPL(vb2_dma_streaming_init_ctx);
+
+void vb2_dma_streaming_cleanup_ctx(void *alloc_ctx)
+{
+ kfree(alloc_ctx);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_streaming_cleanup_ctx);
+
+MODULE_DESCRIPTION("DMA-streaming memory allocator for videobuf2");
+MODULE_AUTHOR("Federico Vaga <federico.vaga@gmail.com>");
+MODULE_LICENSE("GPL v2");
new file mode 100644
@@ -0,0 +1,24 @@
+/*
+ * videobuf2-dma-streaming.h - DMA steaming memory allocator for videobuf2
+ *
+ * Copyright (C) 2012 Federico Vaga
+ *
+ * Author: Federico Vaga <federico.vaga@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_DMA_STREAMING_H
+#define _MEDIA_VIDEOBUF2_DMA_STREAMING_H
+
+#include <media/videobuf2-core.h>
+#include <linux/dma-mapping.h>
+
+void *vb2_dma_streaming_init_ctx(struct device *dev);
+void vb2_dma_streaming_cleanup_ctx(void *alloc_ctx);
+
+extern const struct vb2_mem_ops vb2_dma_streaming_memops;
+
+#endif